Scattering of light may affect why objects look the way they look. Scattering of light may result in objects appearing to have a matt finish, as opposed to shiny or reflective surfaces which have less scattering of light. Intense scattering of light may result in a surface that appears white, such as in the case of white paper, due to the scattering and mixing of incoming light. Scattering of light may be a phenomenon used in various products, which may be known as “smart glass,” which may change their light transmission state from opaque (i.e., scattering most or all incident light) to clear (i.e., scattering little or no incident light) by electric stimulation [1].
The effect of incoherent scattering of light may be due to light travelling through a material while experiencing a modulation in the refractive index of its surrounding (e.g., the material). This modulation may cause light to refract, reflect and/or diffract in substantially random directions, which may cause incoming light of different wavelengths to mix together, resulting in an appearance of the color white.
Types of light-scattering may include, for example: Mie scattering, Tyndall scattering, Rayleigh scattering and Geometric scattering. For scattering of light to occur, typically two or more materials with different refractive indexes may be present. The type of light-scattering produced may be based, for example, on the distance over which the variation of refractive index occurs, the shape or interface between the two or more materials, and/or the magnitude of change in refractive index between the two or more materials.
Rayleigh scattering may occur when the variation in refractive index is on a scale smaller than the wavelength of incident light, for example variations caused by atoms and molecules. Tyndall scattering may occur on a relatively slightly larger scale, for example due to colloids or particles in suspension, such as in milk. Mie scattering may occur when the variation in refractive index is on a scale that may be similar to the wavelength of the incident light, and has been described mathematically for light incident on spherical particles. In both of these types of scattering, shorter wavelengths may be scattered to a greater extent than longer wavelengths. Geometric scattering may occur on a scale larger than the wavelength of the incident light and may be described by the laws of geometric optics.